Multi-buoyancy buoy

ABSTRACT

Multi-buoyancy buoys are described wherein a central, basic buoy has a plurality of arcuate flotation elements removably secured thereabout to selectively provide buoyancy and stability in addition to those of the basic buoy.

United States Patent [1 1 [111 3,893,201 Mallory July 8, 1975MULTI-BUOYANCY BUOY 3,082,439 3/1963 Hornbostel et al. 9/8 F 1694,83?l0/l972 N [75] Inventor: Ray Manmy' Panama CltY 3,803,651 4/l974 9/8 11[73] Assignee: The United States of America as represented by theSecretary of the Primary ExaminerTrygve M. Blix y. ng n. C AssistantExaminerStuart M. Goldstein Attorney, Agent, or Firm-Richard S.Sciascia; Don D. 22 Fl Z 74 I I led Jan 5 l9 Doty; Harvey A. David 211Appl. No.: 436,568

[57] ABSTRACT 52 U.S. Cl 9/8 R 5| 1m. cl. T. B63B 21/52 Mum-bwyancybuoys are descrlbed wherein a [58] Field of Search 9/8 R basic buoy hasa Pluralily of flotation ments removably secured thereabout toselectively [56] References cued provide buoyancy and stability inaddition to those of UNITED STATES PATENTS has:

2.9l0,834 11/1959 Knapp 9/8 R 2 Claims, 5 Drawing Figures MULTI-BUOYANCYBUOY STATEMENT OF GOVERNMENT INTEREST The invention described herein maybe manufactured and used by or for the Government of the United Statesof America for Governmental purposes without the payment of anyroyalties thereon or therefor.

FIELD OF THE INVENTION This invention relates to buoys used for markingcations. supporting scientific instruments and other purposes. Buoysthat are moored are generally provided with ground tackle that includesmooring line. cable, chain, or the like of sufficient scope to preventthe anchor from being dragged by prevailing water currents acting on thebuoy. and also to prevent a buoy of given buoyancy and dimensions frombeing submerged by such currents. Generally, increasing scope of groundtackle increases its holding power while at the same time reduceslikelihood of a buoy being swept under by running currents. There are,of course. practical limits to extension of ground tackle scope. Theseinclude the requirements of handling and maintaining inordinate lengthsof cable, and the increase in the watch circle or radius of travel ofthe buoy. representing a reduction in positioned accuracy.

An alternative measure to prevent a buoy of moderate scope from beingswept under water by swift currents is to use a buoy of greaterbuoyancy. Now, in instances of relatively permanent buoys for markingchannels, and the like, buoy size selection and mooring scope can beeffectively predicated upon experience. and such buoys are not oftenrequired to be moved or retrieved. Accordingly. such buoys are selectedwith substantial amounts of reserve buoyancy and ground tackle holdingpower.

In the case of temporary buoyage. for example in scientific endeavors,the wide variety of water depths, current conditions, and scientificinstrument pay loads which must be met. would require a wide range andvariety of buoys and buoy sizes in order to avoid instances ofinordinately large mooring line scopev DISCUSSION OF THE PRIOR ARTVariable buoyancy buoys have been proposed heretofore, some of whichhave relied upon addition of one or more buoyancy sections. and othersof which have relied upon means increasing the amount of gas in either aflexible or a rigid chamber. US. Pat. No. 2,680,859 to A. A. Hultberg isan example of the added section approach, while US. Pat. No. 3,256,539to A. P. Clark is an example of a flexible chamber technique. The formeris limited to selection of buoyancy by vertical stacking ofsubstantially identical cylindrical float units held together by a rodthrough the common axis of the stacked units. While this provides forbuoyancy selection, the resulting buoy structure tends to lack lateralstability unless ballast. for example in the form of internal concrete.is used. Such ballast. of course. reduces the effective buoyancy. andrenders the buoys more difficult to handle.

The flexible chamber technique is relatively complex. and is more suitedto specialized applications, where remote control of buoyancy isrequired. Moreover. in either of the foregoing types of variablebuoyancy arrangements it is necessary to construct the entire device.rather than continuing to make use ofcxisting buoys.

BRIEF SUMMARY OF THE INVENTION The present invention aims to overcomemost or all of the foregoing shortcomings and disadvantages of the priorart through the provision. in combination with a basic buoy. of add-onflotation means for increasing the buoyancy of the basic buoy and, ifdesired. the stability thereof.

With the foregoing in mind. it is a principal object of this inventionto provide an improved buoy apparatus which will eliminate the highcosts and inconvenience of providing a number of conventional buoys in aplurality of sizes.

Another important object of the invention is the provision of a buoyassembly comprising a basic buoy and a plurality of arcuate flotationelements fixed about said basic buoy so as to increase buoyancy andstability thereof, the arcuate flotation elements being removable foruse of the basic buoy alone. or for replacement by other arcuateflotation elements. whereby a composite buoy having the most desirabledegree of buoyancy for a particular water depth. current. and mooringscope can be assembled in a short time.

Still another object is the provision of a multiple buoyancy buoyapparatus of the foregoing character. wherein the flotation elements areformed principally of a rigid plastic foam, such as expandedpolystyrene. covered by a durable skin of a compatible plastic resin.preferably incorporating a suitable reinforcing material such as glassfiber.

Other objects and many of the attendant advantages will be readilyappreciated as the subject invention becomes better understood byreference to the following detailed description, when considered inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of a multiplebuoyancy buoy embodying the invention;

FIG. 2 is a sectional view of the buoy of FIG. 1, taken substantiallyalong line 22 thereof;

FIG. 3 is a diagrammatic illustration depicting operation of the buoy ofFIG. 1;

FIG. 4 is a plan view of another embodiment of the invention; and

FIG. 5 is a side view, partly in elevation and partly in section. of theembodiment of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the form of the inventionillustrated in FIGS. 1 and 2, a multi-buoyancy buoy. generally indicatedat I0, comprises a basic buoy l4 and a buoyancy increasing flotationassembly 16 mounted on basic buoy 14 in encircling relation thereto.Basic buoy I4, in this exemplary embodiment, comprises a circular hullMa. as viewed in plan. from which depends an annular keel 14]). Hull 14ais characterized by a substantially flat top deck 14c. a substantiallyflat bottom surface 14d. and a side wall He presenting a substantialdcadrise or flare.

Depending from the bottom surface 14d, on diametrically opposite sidesof keel 14b, are a pair of apertured flanges or eyes 18 that serve aspivotal connections for a bail 20. Bail 20 serves as a connection meansfor mooring gear or ground tackle, such as includes a cable 22 securedto the bail by a shackle 24. Cable 22 may be secured to any suitableform of anchor for the circumstances in which buoy is to be moored, andcable 22 may have a scope commensurate therewith as will later bediscussed with reference to FIG. 3. Basic buoy 14 may further beprovided with any other fitment to suit it for scientific or otherpurposes, a central vertical antenna mast 26 being illustrated asrepresentative thereof.

The buoyancy increasing flotation assembly 16 comprises a plurality,four in this example. of arcuate flotation elements 28 joined togetherin a circle in embrac' ing relation to basic buoy 14. Each arcuateflotation element 2 is conveniently formed of a tough, durable. skin orshell 30, preferably molded of a material such as fiberglass reinforcedpolyester resin, and a cellular, rigid plastic foam core 32, preferablycomprising expanded polystyrene or polyurethane material. The innerarcuate surface of each flotation element 28 is desirably molded orshaped so as to be complementary to the shape of the side wall l4e ofhull 14 so as to provide a snug fit thereagainst when assembled.

inwardly directed ears or tangs 34 are provided, conveniently as anintegrally molded portion of shell 30, with one such tang extendingradially from each end of each flotation element 28. Tangs 34, which aredisposed in congruent pairs in the assembled buoy 10, are apertured toreceive bolts 38, or other suitable fasteners. Because tangs 34 overliethe deck [40 of basic buoy l4, and because of the complementary shapingof surfaces of the flotation elements adjacent thereto, the flotationelements are firmly secured in position on the basic buoy without anyspecific fixtures being necessary on the latter.

MODE OF OPERATION Referring to FIG. 3, consider a basic buoy 14 to bemoored in water W by means of ground tackle including cable 22 and asuitable anchor A on the bottom B. Consider also that, with a scope ofsay 2:1, and a current running of velocity V, buoy 14 will just floatsatisfactorily to perform its position indicating, scientific datatransmitting, or other design function. In this condition basic buoy 14has a watch circle radius of R. Now, if the current increases invelocity to V, basic buoy [4 will no longer have adequate buoyancy, witha cable scope of 2:1 to perform its intended function. Rather, it willbe swept underwater to some position such as that indicated in dottedlines. This circumstance has generally been met in the past simply byincreasing the cable scope as shown in FIG. 3 by basic buoy l4 and cable22'. The result is a greatly increased watch circle radius R, oftenunacceptable in terms of scientific accuracy.

In accordance with the present invention, however, the watch circleradius R can be retained in spite of the greater current V, by retainingthe cable 22 of lesser scope and adding flotation assembly 16 elements28 to basic buoy 14 to arrive at multiple buoyancy buoy l0. Buoy 10will, as shown in FIG. 3, provide the desired smaller watch circleradius R with the shorter cable 22, even at current V. By having anumber of flotataion assemblies 16 of different displacements, it ispossible to meet a wide range of buoyancy requirements with a singlebasic buoy 14.

It will be recognized that the flotation elements 28 not only increasethe buoyancy of buoy H], but also we tend the beam thereof in such amanner as to render buoy l0 considerably more stable than basic buoy 14.

Referring now to FIGS. 4 and 5, another embodiment of multi-buoyancybuoy is indicated generally at 40, this embodiment being preferred forlighter duty than that previously described. Buoy 40 comprises a cylindrical basic buoy 42 in combination with an assembly of arcuateflotation elements. Basic buoy 42 is provided with a suitable mast 44extending axially through the cylindrical body thereof, which body mayconveniently be formed of a suitable expanded plastic resin material,such as polystyrene. A mooring eye 44a is formed at the lower end ofmast 44, below the cylindrical body.

The arcuate flotation elements comprise a pair of semicylindricalelements 460 and 46h snugly encompassing the body of basic buoy 42.Elements 46a and 46b are also conveniently formed of an expanded plasticfoam material such as polystyrene. and each is substantially of the sameheight as the basic buoy body. Another pair of arcuate, semi-cylindricalflotation elements 48a and 48b are disposed in snug encompassingrelation to the lower half or so of flotation elements 460 and 46b. Aband 50 of plastic or corrosion resistant metal surrounds flotationelements 48a, 48b and binds those elements, as well as elements 46a, 46bto the basic buoy body.

Vertically stacked on elements 48a, 48b are a substantially identicalpair of arcuate. semi-cylindrical flotation elements 52a and 52b, insnugly encompassing relation to the upper half or so of flotationelements 46a. 46b. Another band 50 binds elements 52a, 52b, elements46a, 46b, and the basic buoy together.

Buoy 40 comprises, therefore, in addition to basic buoy 42, a number offlotation elements which increase the buoyancy above that of the basicbuoy alone. It will be recognized that one or more of the pairs offlotation elements may be omitted from the combination. desired toprovide a buoy 40 having the degree of buoyancy desired.

Obviously, other embodiments and modifications of the subject inventionwill readily come to the mind of one skilled in the art having thebenefit of the teachings presented in the foregoing description and thedrawings. It is, therefore, to be understood that this invention is notto be limited thereto and that said modifications and embodiments areintended to be included within the scope of the appended claims.

What is claimed is:

l. A multiple bouyancy bouy comprising in combination:

a basic bouy for providing a first predetermined amount of positivebouyancy, said basic bouy comprising a hull that is circular in plan,has a substantially flat bottom surface of a first diameter, asubstantially flat deck surface of a second diameter that is larger thansaid first diameter, and an annular side wall presenting a curved.sloping outer surface extending upwardly and outwardly from theperiphery of said bottom surface to the periphery of said deck;

a plurality of arcuate flotation elements assembled in the form of aring and embracing said basic bouy so as to provide additional bouyancy,each of said elements comprising only a segmental section of said ringand presenting a curved and sloping inner tion to a tang of another ofsaid flotation elements and said tangs being free of direct connectionto said bouy; and

releasable fastener means securing together mutually adjacent ones ofsaid tangs.

2. A multiple bouyancy bouy as defined in claim I,

and wherein:

said ring comprises four of said arcuate flotation elements. and eachsegmental section extends substantially one quarter of a circle.

1. A multiple bouyancy bouy comprising in combination: a basic bouy forproviding a first predetermined amount of positive bouyancy, said basicbouy comprising a hull that is circular in plan, has a substantiallyflat bottom surface of a first diameter, a substantially flat decksurface of a second diameter that is larger than said first diameter,and an annular side wall presenting a curved, sloping outer surfaceextending upwardly and outwardly from the periphery of said bottomsurface to the periphery of said deck; a plurality of arcuate flotationelements assembled in the form of a ring and embracing said basic bouyso as to provide additional bouyancy, each of said elements comprisingonly a segmental section of said ring and presenting a curved andsloping inner surface complimentary to and adjacent a correspondingportion of said sloping outer surface of said side wall, whereby upwardmovement of said ring relative to said basic bouy is precluded bycooperation between said outer and inner surfaces; each of saidflotation elements further comprising a plurality of tangs eachextending radially inwardly from one end thereof in overlying relationto said deck, whereby said ring is prevented from downward movementrelative to said basic bouy, each of said tangs being disposed inmutually adjacent relation to a tang of another of said flotationelements and said tangs being free of direct connection to said bouy;and releasable fastener means securing together mutually adjacent onesof said tangs.
 2. A multiple bouyancy bouy as defined in claim 1, andwherein: said ring comprises four of said arcuate flotation elements,and each segmental section extends substantially one quarter of acircle.